Testes para desinfestação de explantes do cacaueiro visando estabelecimento in vitro

Abstract

With the increasing demand for chocolate and its derivatives, there is also a growing need for healthy cocoa seedlings with high genetic potential, often not contemplated in conventional asexual multiplication or by seeds. In this sense, the objective of this work was to test different products for disinfestation of cacao explants for their establishment in vitro. Two tests were performed at Bioclone Produção de Mudas LTDA. In the first, the explants used were nodal segments from field plants of genotypes PS 1319 and CCN 51. Sodium hypochlorite 1.5% or chlorine dioxide 0.025% was tested in disinfestation, and growth media with or without chlorine dioxide. In the second, the explants were apical buds of young plants of the genotype PS 1319 cultivated in greenhouse. Disinfestation was tested with sodium hypochlorite (3% or 6%) or with chlorine dioxide (3% or 5%). Faced with the contamination of 100% of the nodal segments of the first test, it was found that the concentrations of the products used were not sufficient to disinfect them and that chlorine dioxide in the growth media does not cause chemical sterilization. For asepsis of apical buds of cacao trees kept in greenhouse, the use of sodium hypochlorite at 6% did it impossible to develop in vitro contaminations. To reduce oxidation losses, the transfer of the explants to another growth media must occur before 21 days. The adjustment in the concentrations of the products used and the use of antioxidant agents may help to obtain an effective protocol for disinfestation of cocoa explants.